package com.luoyulin.stack;

import java.util.Scanner;

/**
 * @author luoyulin
 * @create 2022-01-14 22:49
 **/
public class ArrayStatckDemo {
    public static void main(String[] args) {
        ArrayStack arrayStack = new ArrayStack(4);
        String key = "";
        boolean loop = true;
        Scanner scanner = new Scanner(System.in);
        while (loop){
            System.out.println("show 显示栈");
            System.out.println("exit 退出");
            System.out.println("push 入栈");
            System.out.println("pop 出栈");
            key = scanner.next();
            switch (key){
                case "show":
                    arrayStack.showStack();
                    break;
                case "push":
                    System.out.println("输入一个数：");
                    int value = scanner.nextInt();
                    arrayStack.push(value);
                    break;
                case "pop":
                    try {
                        int res = arrayStack.pop();
                        System.out.printf("出栈的数据为%d\n",res);
                    }catch (Exception e){
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop = false;
                    break;
                default:
                    break;
            }
        }
        System.out.println("退出程序！！");
    }
}

class ArrayStack{
    private int maxSize;
    private int[] stack;
    private int top = -1;
    public ArrayStack(int maxSize){
        this.maxSize = maxSize;
        stack = new int[this.maxSize];
    }
    //判断是否为满
    public boolean isFull(){
        return top == maxSize - 1;
    }
    //判断是否为空
    public boolean isEmpty(){
        return top == -1;
    }
    //入栈
    public void push(int value){
        if(isFull()){
            System.out.println("满了");
            return;
        }
        top++;
        stack[top] = value;
    }
    //出栈
    public int pop(){
        if(isEmpty()){
            throw new RuntimeException("栈空");
        }
        int value = stack[top];
        top--;
        return value;
    }
    //遍历栈
    public void showStack(){
        if(isEmpty()){
            System.out.println("没有数据");
            return;
        }
        for (int i = top; i >= 0 ; i--) {
            System.out.printf("stack[%d] = %d\n",i,stack[i]);
        }
    }

}
